What test is used to differentiate Micrococcus from Staphylococcus species?

The primary method used to differentiate Micrococcus from Staphylococcus species is the catalase test. Both genera are Gram-positive cocci, but they can be distinguished based on their catalase production. Staphylococcus species produce the enzyme catalase, which breaks down hydrogen peroxide into water and oxygen, resulting in gas bubbles during the test. In contrast, Micrococcus species also produce catalase but may often be found in a distinctive arrangement or have a different oxidative profile.

While glucose fermentation, gram staining, and other biochemical tests might provide useful information, they are not as definitive for differentiating these two groups as the catalase test. The catalase test is quick and reliable, making it a standard method for microbiologists to differentiate these similar-looking microorganisms.

Thus, the best answer for distinguishing Micrococcus from Staphylococcus is indeed the catalase test, as it directly assesses the presence of catalase enzyme production, which is a key characteristic of Staphylococci.